Im still unsure on what you are wanting, but heres something that could find the time.
Code:
$gettok($gettok($1-,1,58),-1,32) $+ : $+ $gettok($gettok($1-,2,58),1,32) 


This probably could be done better with tokenize or even better with regular expressions. But this will do just fine for what you need it for (well what I think you need it for)